Photographic material as referred to herein is understood to be generally planar, may comprise film or paper, may produce a black-and-white or color image, and may be in a continuous web form or may comprise discrete sheets.
Silver halide photographic materials are well-known, and are processed to generate a silver or dye image via a development stage followed by a series of baths to stabilize and provide permanence to the image. Such baths convert and remove unwanted materials from the coated photographic layers which would either interfere with the quality of the final image or cause degradation of the image with time. In typical color systems the development stage is followed by a bleach stage to oxidize the developed silver to a form which can be dissolved by a fixing agent in the same or a separate bath. Such silver removal stages are then followed by a washing stage using water, or other wash solution, or a stabilization stage using a stabilizer solution. For convenience, this last-mentioned stage will hereinafter be referred to generically as "washing". Such stages remove residual chemicals and may also include conversion reactions between stabilizer solution components and materials within the coated layers. These stages are required to provide the required degree of permanence to the final image.
EP-A-0 762 205 and U.S. Pat. No. 5,537,179 disclose apparatus in which photographic material is washed using wash tanks. The photographic material is guided down into a wash tank through successive pairs of horizontally-disposed rollers, and water is directed downwardly into the nips thereof. A simple multi-stage washing device is thus obtained.
The application of washing liquid as exemplified in the above-mentioned publications results in the liquid flowing over the ends of the rollers rather than remaining in the nip, which leads to excessive quantities of liquid being used. Many solutions to this problem have been suggested, including the use of O-ring seals at the ends of the rollers, housings that fit tightly around the rollers, and convex or concave roller ends. All of these solutions, however, are mechanically complex and eventually result in unacceptable wear of the sliding or rolling surfaces. The use of magnetic fluids and magnetic containment is known, but this also results in a rather complex arrangement.